The purpose of the proposed SBIR project is to investigate the use of High Intensity Focused Ultrasound for the treatment of esophageal tissue, with the ultimate goal of developing an ultrasound ablation system for the treatment of Barrett's Esophagus, a pre-cancerous condition that affects approximately 2 million Americans. Although current therapies for Barrett's Esophagus exist, no successful treatment, which significantly improves the patient's quality of life, is available. The proposed project will lead to a new therapeutic approach, which will be available to physicians worldwide to treat the disorder. Phase I of the project will concentrate primarily on determining whether ultrasound can be effectively focused and ablate the thin layer of esophageal tissue without damaging underlying tissues. Excised esophagus will be used to characterize tissue ultrasonically. These biophysical data will be used in computer simulations to design an appropriate ultrasound therapeutic system in Phase II. Excised esophagus from both human and porcine will be measured and compared ultrasonically so that a porcine model can be used for in vivo studies in Phase II. Differences and similarities between human and porcine tissue will be incorporated into the model. Significant societal benefits will be realized in terms of improved quality of life, rapid patient recovery, and reduced medical costs. Resulting benefits will also include increased economic activity in terms of medical device manufacturing.